相关论文: Rapid Gamma-ray variability of NGC 1275

By studying the variability of blazars across the electromagnetic spectrum, it is possible to resolve the underlying processes responsible for rapid flux increases, so-called flares. We report on an extremely bright X-ray flare in the…

This paper combines data from the three preceding papers in order to analyze the multi-waveband variability and spectral energy distribution of the Seyfert~1 galaxy NGC~4151 during the December 1993 monitoring campaign. The source, which…

In 2006 the stand-alone MAGIC-I telescope discovered very high energy gamma-ray emission from 3C279. Additional observations were triggered when the source entered an exceptionally bright optical state in January 2007 and the Fermi space…

The mechanisms producing fast variability of the $\gamma$-ray emission in active galactic nuclei are under debate. The MAGIC telescopes detected a fast very high energy (VHE, E$>100$ GeV) $\gamma$-ray flare from BL Lacertae on 2015 June 15.…

The $\gamma$-ray flare of PKS 1222+216, observed in June 2010, is interpreted as an outcome of jet dynamics at recollimation zone. We obtained the $\gamma$-ray light-curves in three different energy bands, namely, 100--300 MeV, 300 MeV--1…

We have reanalyzed the giant outburst of the blazar PKS 1510-089 (z=0.36) that occurred on 2011 October-November. The gamma-ray flux in the 0.1-100 GeV energy range exceeded the value of 10^-5 ph/cm2/s for several days. The peak flux was…

A multiwavelength temporal and spectral analysis of flares of 3C 279 during November 2017--July 2018 are presented in this work. Three bright gamma-ray flares were observed simultaneously in X-ray and Optical/UV along with a prolonged…

We report the first detection of GeV gamma-ray flaring activity from the compact symmetric object (CSO)-like source 4C 76.03, based on 17 years of Fermi-LAT observations. Its long-term, time-averaged gamma-ray properties are consistent with…

The X-ray, Ultraviolet, Optical emission from radio-quiet AGNs, black hole binaries, and other compact sources, in general, follow a lognormal flux distribution, a linear rms-flux relation, and a (broken) power-law power spectral densities…

We study the variability mechanism of active galactic nuclei (AGN) within the framework of the flare model. To this end we examine the case of Seyfert/LINER galaxy NGC 4258, which is observed at high inclination angle and exhibits rapid…

Among active galactic nuclei (AGNi), blazars are the brightest emitters of high-energy (HE, $E \geq 100$ MeV) to very-high-energy (VHE, $E \geq 100$ GeV) $\gamma$-rays from their jets. Radio galaxies, being the misaligned parent population…

We have analysed the first 15 months of Fermi/LAT data of the radio loud quasar 3C 273. Intense gamma-ray activity has been detected, showing an average flux of F(> 100 MeV) = 1.4e-6 ph/cm^2/s, with a peak at F(> 100 MeV) = 5.6e-6 ph/cm^2/s…

We present a study of optical, UV and X-ray light curves of the nearby changing look active galactic nucleus in the galaxy NGC 1566 obtained with the Neil Gehrels Swift Observatory and the MASTER Global Robotic Network over the period 2007…

We report the analysis of the gamma-ray variability of NGC 1275--the radio galaxy at the center of the Perseus cluster. NGC 1275 has been observed continuously with the Fermi Large Area Telescope over the last nine years. We applied…

Significant flares of GeV $\gamma$-ray emission from the Crab Nebula have been found by AGILE and Fermi-LAT years ago, indicating that extreme particle acceleration and radiation occurs in young pulsar wind nebulae. To enlarge the flare…

CTA 102 is a $\gamma$-ray bright blazar that exhibited multiple flares in observations by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope during the period of 2016-2018. We present results from the analysis of…

Recent detection of suborbital gamma-ray variability of Flat Spectrum Radio Quasar (FSRQ) 3C 279 by Fermi Large Area Telescope (LAT) is in severe conflict with established models of blazar emission. This paper presents the results of…

We present a comprehensive analysis of the 17-year Fermi-LAT observational data of Mrk 421 to investigate the spectral variations in the $\gamma$-ray bands. The light curve of the source in the 0.1--1000 GeV band with a 14-day time bin…

We present a detailed Fermi/LAT data analysis for the broad-line radio galaxy 3C 120. This source has recently entered into a state of increased gamma-ray activity which manifested itself in two major flares detected by Fermi/LAT in…

We search for gamma-ray emission from OJ287 in the energy range from 0.1-300 GeV during 2015-2023, in coincidence with an extensive observing campaign to monitor the optical flux variability and polarization, as discussed in…